Optical device and camera system

Abstract

An optical device includes a base member, an image-stabilizing lens, a lens holding member mounted to the base member and configured to hold the image-stabilizing lens, a driving unit configured to drive the lens holding member in a direction orthogonal to an optical axis, a plurality of elastic members fixed between the base member and the lens holding member, a vibration detecting unit configured to detect vibration, and a control circuit configured to control the position of the lens holding member on the basis of vibration information from the vibration detecting unit. The center position of the driving range of the image-stabilizing lens is controlled on the basis of vibration information obtained during a predetermined period between the time when a first trigger signal is input and the time when a second trigger signal is input.

1. An optical device comprising:
 a base member; 
 an image-stabilizing lens; 
 a lens holding member mounted to the base member and configured to hold the image-stabilizing lens; 
 a driving unit configured to drive the lens holding member in a direction orthogonal to an optical axis; 
 a plurality of elastic members fixed between the base member and the lens holding member; 
 a vibration detecting unit configured to detect vibration; and 
 a control circuit configured to control the position of the lens holding member on the basis of vibration information from the vibration detecting unit, 
 wherein the center position of the driving range of the image-stabilizing lens is controlled on the basis of vibration information obtained during a predetermined period between the time when a first trigger signal is input and the time when a second trigger signal is input. 
 
   
   
     2. An optical device as claimed in  claim 1 , wherein the center position is controlled to be within a range between the optical axis of the image-stabilizing lens and the optical axis of the image-capturing optical system in a state in which the image-stabilizing lens is held on the elastic members by gravity. 
   
   
     3. An optical device as claimed in  claim 2 , wherein the center position is controlled with reference to a position of the image-stabilizing lens held on the elastic members by gravity when a first vibration output from the vibration detecting unit is less than or equal to a first output value, and is controlled with reference to a position of the image-stabilizing lens lifted from the position held on the elastic members by gravity toward the optical axis of the image-capturing optical system when a second vibration output from the vibration detecting unit is larger than the first vibration output. 
   
   
     4. A camera system comprising:
 an interchangeable lens; and 
 a camera on which the interchangeable lens is detachably mounted, 
 wherein the interchangeable lens includes: 
 a base member; 
 an image-stabilizing lens; 
 a lens holding member mounted to the base member and configured to hold the image-stabilizing lens; 
 a driving unit configured to drive the lens holding member in a direction orthogonal to the optical axis; 
 a plurality of elastic members fixed to the base member and the lens holding member; 
 a vibration detecting unit configured to detect vibration; and 
 a control circuit configured to control the position of the lens holding member on the basis of vibration information from the vibration detecting unit, 
 wherein the camera includes: 
 a release switch configured to output a first trigger signal indicating an image-capturing preparatory state, and a second trigger signal indicating an image capturing state, and 
 wherein the interchangeable lens controls the center position of the driving range of the image-stabilizing lens on the basis of vibration information obtained during a predetermined period between the time when the first trigger signal is output and the time when the second trigger signal is output. 
 
   
   
     5. A camera system as claimed in  claim 4 , wherein the center position is controlled to be within a range between the optical axis of the image-stabilizing lens and the optical axis of the image-capturing optical system in a state in which the image-stabilizing lens is held on the elastic members by gravity. 
   
   
     6. A camera system as claimed in  claim 5 , wherein the center position is controlled with reference to a position of the image-stabilizing lens held on the elastic members by gravity when a first vibration output from the vibration detecting unit is less than or equal to a first output value, and is controlled with reference to a position of the image-stabilizing lens lifted from the position held on the elastic members by gravity toward the optical axis of the image-capturing optical system when a second vibration output from the vibration detecting unit is larger than the first vibration output.